CARACAS, Jan 8 (Reuters) - Venezuela's opposition demanded
on Tuesday to know if President Hugo Chavez was well enough to
be sworn in for a new term this week, and two Latin American
leaders confirmed they would come even in his absence.

The government says the formal Jan. 10 start of the
cancer-stricken Chavez's new six-year term can be postponed with
no consequences, while the opposition says a caretaker president
should be appointed if Chavez is unable to be sworn in.

The 58-year-old socialist leader, who has dominated the
South American OPEC nation since 1999, has not been seen or
heard from in public since his Dec. 11 cancer surgery in Cuba.

Official medical bulletins suggest he is too sick to return
for Thursday's swearing-in ceremony - though Venezuela's
government has not confirmed that.

"I really lament that just 48 hours away the government is
incapable of telling Venezuelans if President Chavez is or is
not going to be taking office," opposition leader Henrique
Capriles, who lost last year's presidential election to Chavez,
said in a press conference.

Capriles is expected to run again for the presidency if
Chavez dies or is unable to return to office, and a new election
is triggered.

"I don't understand why it's so difficult for them to speak
the truth," Capriles added, urging the Supreme Court to provide
a legal interpretation of the constitution.

Political acrimony over the Jan. 10 swearing-in has taken
the focus away from Chavez's physical condition: the government
acknowledges he has a serious lung infection after the
operation, but denies rumors he is on his death-bed.

The Supreme Court, dominated by Chavez allies, is expected
to rule on a vague constitutional article which lays out Jan. 10
as the inauguration date but does not explicitly state what
happens if a president is not sworn in at that time.

NATIONAL CONFUSION

On the street, Venezuelans are bemused and anxious.

Supporters hold vigils for Chavez's recovery, while
opposition activists accuse the president's allies of a
Cuban-inspired manipulation of the situation.

Vice-President Nicolas Maduro, who Chavez last month named
as his successor, has taken over day-to-day running of
government and looks set to continue in the role past Thursday.

The mustachioed former bus driver lacks Chavez's charisma
and deep popularity among Venezuelans, but has been seeking to
imitate his style with rambunctious attacks on the opposition
and televised, ribbon-cutting ceremonies.

"Venezuela is not a monarchy. Ours is not the Cuban system
where power is passed around without an election," said
Capriles, who argues that National Assembly head Diosdado
Cabello should take over on Jan. 10 as mandated by the
constitution if there is a formally-declared absence of the
president.

The opposition Democratic Unity coalition, whom Capriles ran
for in the 2012 vote, has taken its constitutional complaint to
the hemispheric Organization of American states - though it has
garnered little support in the region.

Rather, Latin American heavyweight Brazil has said it
believes Venezuela's government is sticking to the constitution.

The U.S. government, so long the target of Chavez's ire, has
said it is up to Venezuelans to decide their future - though it
angered Caracas by calling Chavez's policies "authoritarian."

At least two fellow leftist presidents - Evo Morales of
Bolivia and Jose Mujica of Uruguay - are coming to Caracas for
Thursday's ceremony, where it appears there will be a rally in
solidarity with the ailing Chavez in place of the inauguration.

Argentina's left-leaning President Cristina Hernandez has
announced plans to visit Chavez in Havana on Friday, a move that
would appear to confirm that Chavez will miss the swearing-in
even though Cabello said there was a chance he could attend.

Underlining the gravity of his condition, Mujica's wife said
the Uruguayan leader had been dissuaded from visiting Cuba.

"He first checked if he could go to Havana. But he (Chavez)
cannot be seen. So I think going to Havana would be a bother,"
Mujica's wife, Lucia Topolansky, said in a radio interview.

"With all respect, I urge our Latin American presidents not
to play the game of one political party," Capriles added at his
news conference, saying the ruling Socialist Party was trying to
cook up Venezuela's future over the heads of the people.

With the micro-managing and authoritarian Chavez away, major
policy decisions in Venezuela, such as a widely-expected
devaluation of the bolivar currency, appear to be on hold.

Opposition predictions of in-fighting within the Socialist
Party have not materialized, with Maduro and Cabello in
particular pledging unity despite rumors of rivalry.

Having failed to topple Chavez a decade ago with sustained
street protests and national strikes, the opposition's tactics
are to show respect for his health problems while criticizing
the legalities of the situation and preparing for a possible new
presidential election later in 2013.

Venezuelan bond prices, which had soared in recent weeks on
Chavez's health woes, dipped on Monday and Tuesday as investors'
expectations of a quick government change apparently dimmed.

"The 'regime change' euphoria seems excessive taking into
account the unclear legal transition and perhaps, more
importantly, the risk that regime change does not allow for
policy change," New York-based Jefferies' managing director
Siobhan Morden said in a note on the bonds.
(Additional reporting by Alejandro Lifschitz in Buenos Aires,
Malena Castaldi in Montevideo and Danny Ramos in La Paz; Editing
by Paul Simao)